LONDON, (Reuters) – European police agency Europol  expects further arrests in connection with suspected carbon  credit tax fraud after Britain’s tax office said two more people  were arrested in London late yesterday, bringing the total to  nine.

Officers from HM Revenues and Customs (HMRC), working with  Europol, have now arrested seven men and two women following a  suspected 38 million pounds ($62.8 million) value-added tax  (VAT) scam related to carbon credit trading.

“Our experts were present a few days ahead planning this  operation together with HMRC. Beforehand there was a huge  investigation going on and more arrests are expected,” said  Europol’s chief of media Soren Kragh Pedersen.

“We are on the lookout in the rest of Europe of course.”

HMRC raided 27 businesses and homes around London early on  Wednesday. A spokeswoman told Reuters on Thursday that all the  people who had been arrested had been bailed and no charges had  been brought.

HMRC said the arrests are related to an investigation into  what is believed to be an organised crime group operating a  network of companies trading large volumes of European Union  carbon emissions credits in so-called carousel fraud.

Through carousel fraud, also called missing trader fraud,  fraudsters import goods VAT-free from other countries, then sell  the goods to domestic buyers, charging them VAT. The sellers  then disappear without paying the tax to the government.

Britain said last month it would make carbon trading exempt  from VAT in response to the suspected scam.